1. Field of the Invention
The present invention relates to an improvement in solderless electrical connectors to afford the same greater integrity and in one aspect to the improved mechanical locking features of the connectors and their ability to accommodate a variety of wire sizes.
2. Description of the Prior Art
The prior art is replete with patents utilizing the invention of the insulation displacing wire connection as disclosed in U.S. Letters Pat. No, 3,012,219. This patent discloses a connector comprising a base member, a wide U-shaped resilient conductive connector member and a cap fitting in a corresponding opening in the thickened upper portion of the base. U.S. Letters Patent No. Des. 191,399 discloses the stylized version of the connector and the general appearance of the connector as it has been sold by the assignee of the present invention for many years. The connector has undergone changes and improvements resulting in a variety of similar products but failing to provide the features of the present invention. Examples of these modifications include the teachings of U.S. Pat. Nos. 3,573,713; 3,656,088; 3,804,971 and 3,936,128.
Patent No, 3,012,219 and 3,656,088 disclose U-shaped resilient contact elements. In the earlier patent the slots 17 and 19 are adapted to join copper telephone wires of No. 19 to No. 26 gage and the contact element 15 is formed of 0.025 in. cartridge brass. The slots are adapted for redundant connections to the wires wherein the slots of the contact element shown in Pat. No. 3,656,088 are of different sizes to make connection with plastic coated aluminum wires. Similar connectors are marketed wherein the wider slots are used with connectors for copper wire with the wider slots affording strain relief.
The prior connectors, identified in the trade as assignee's UY connectors, were made of a stiff polycarbonate material and the connector member was formed of 260 cartridge brass of full hardness. The connector member comprised two wire connecting slots and the area between the slots in each connecting plate was not slotted. The UY connectors were not recommended for 19 gage wire and was not usable with some wires having thicker insulation.
Patent No. 3,936,128 discloses a solderless connector having a U-shaped contact 40 for connecting two wires disposed in a base 20. The contact 40 has two wire connecting slots with expansion slots 42 between the slots 41. The slots 41 have a key hole configuration to distribute the stresses created by connection to the wires.
In order to achieve a connector which will accommodate the wider range of wire sizes, i.e. No. 19 to No. 26, and which can be made of a less expensive material and which can withstand the stress associated with temperature change, lightning strikes, and other environmental causes, it was recognized that the connector had to be redesigned to have the same integrity.
The materials, generically at least, are not new and are not new to the connector area but the specific selection of these materials and the specific construction of the elements of the connectors are novel. The problems created by the mere change in materials requires the exercise of the inventive facility and in the connector of the present invention includes cooperative relationships between the elements which are not present in the prior art.